carg(3)                                               Library Functions Manual                                              carg(3)

NAME
       carg, cargf, cargl - calculate the complex argument

LIBRARY
       Math library (libm, -lm)

SYNOPSIS
       #include <complex.h>

       double carg(double complex z);
       float cargf(float complex z);
       long double cargl(long double complex z);

DESCRIPTION
       These  functions  calculate  the  complex argument (also called phase angle) of z, with a branch cut along the negative real
       axis.

       A complex number can be described by two real coordinates.  One may use rectangular coordinates and gets

           z = x + I * y

       where x = creal(z) and y = cimag(z).

       Or one may use polar coordinates and gets

           z = r * cexp(I * a)

       where r = cabs(z) is the "radius", the "modulus", the absolute value of z, and a = carg(z) is the "phase angle",  the  argu‐
       ment of z.

       One has:

           tan(carg(z)) = cimag(z) / creal(z)

RETURN VALUE
       The return value is in the range of [-pi,pi].

VERSIONS
       These functions were added in glibc 2.1.

ATTRIBUTES
       For an explanation of the terms used in this section, see attributes(7).

       ┌─────────────────────────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │Interface                                                                                        │ Attribute     │ Value   │
       ├─────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │carg(), cargf(), cargl()                                                                         │ Thread safety │ MT-Safe │
       └─────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

STANDARDS
       C99, POSIX.1-2001, POSIX.1-2008.

SEE ALSO
       cabs(3), complex(7)

Linux man-pages 6.03                                         2022-12-15                                                     carg(3)